The invention relates to a control unit for a domestic appliance, especially for a washing machine of the type specified in the pre-characterizing clause of claim 1.
A control unit of this kind is, for example, already known from DE 103 08 204 B3, with a control button, indicator or similar arranged within a panel opening of a fascia panel. At a distance behind the fascia panel or control buttons or indicators or similar, a board is arranged that serves to hold at least one electrical or electronic component. In order to protect the at least one electrical or electronic component against water entering via the fascia panel, a sealing element formed as a sealing layer is arranged between this and the board. The sealing element is directly attached to the board by a plurality of attaching areas that are provided between, or outside, the electrical or electronic components.
A disadvantage with an arrangement of this kind of sealing element is, however, that the board has to be of relatively large construction in order to be able to attach the sealing element over the attaching areas. In other words, the individual electrical or electronic components can only be arranged on the board at a relatively large distance from each other because board areas have to be provided between these at which the sealing element can be attached. Something else that must also be regarded as disadvantageous is the fact that water entering via the fascia panel or between this and the control buttons, indicators or similar has to be led out of the area between the mounting panel and sealing element in a relatively complicated manner, by means of drain openings arranged within the sealing element.
A further control unit is known from DE 10 2004 048 755 A1. Opposite a housing that carries a circuit board holding several micro switches, an assembly is mounted that itself includes a front wall and rear wall serving as fascia panels. Both the front wall and the rear wall are each pierced by openings through which switch plungers to operate the respective micro switches project. The front wall and rear wall of the control elements are furthermore arranged at a considerable distance from each other in the area of which a sealing element in the form of resilient sealing mat with through openings for the plungers is arranged. The sealing mat also lies flat, flush against the inner surface of the front wall. Furthermore, the sealing mat is in contact with the outer circumference of the corresponding plunger forming a tight seal over a corresponding length. Each plunger is surrounded at the rear wall end by a cap which is assigned to the sealing mat. The sealing mat is thus supported by resting on the inner surface of the back of the fascia panel against the rear wall.
A disadvantage of this known control unit is the fact that it is extraordinarily difficult to seal in the area of the plunger. This is especially due to the fact that in each case there has to be a mechanical decoupling between each two adjacent plungers by means of a suitable shaping so that when one of the buttons on the front assigned to the respective plunger is pressed the adjacent plunger is moved with it. Due to the corresponding loose arrangement of the sealing mat required on the inner surface of the front wall serving as a fascia panel, it is therefore possible that water can penetrate into the space between the front and rear wall. For this reason, a water drain has to be provided in the area between the front and rear wall on the one hand and on the other hand it is necessary for the sealing element to be correspondingly reliably sealed with respect to the plungers. Both methods incur significant production costs.